The present invention relates to compositions or preservatives for use in industrial products, which protect these products against bacterial and fungal infestation over extended service lives.
Preservatives having a biocidal action for use in industrial products such as cutting fluids, cutting fluids which have been mixed with water, industrial emulsions or other water-based industrial products, and also for household products, such as, for example, cleaning products or cosmetics, such as, for example, bodycare products, are when required generally added to the products to be preserved in low concentration in the form of concentrates.
They protect these products against infestation by bacteria, fungi and yeasts and contribute to long service lives of industrial products, such as, for example, cutting fluids which have been mixed with water, and to a long useful life of household products and cosmetic products.
During their manufacture, storage and their use, preservatives are subject to certain requirements which arise inter alia from the way in which they are added to the abovementioned products in the form of liquid concentrates.
A known fungicidal active ingredient which is frequently used today is iodopropynylbutyl carbamate (IPBC), which is marketed, for example, by Troy Chemie as an organic fungicide preparation in the form of a 20% strength solution of the active ingredient in glycols under the trade name Troyshield F20.
In order to achieve a likewise satisfactory bactericidal effect, it is, however, necessary to combine IPBC with other active substances, e.g. formaldehyde donor compounds. Regarding compatibility with IPBC, however, there are problems when used in concentrates containing formaldehyde donor compounds in the form of strongly alkaline bactericides. Thus, for example, Troy Chemie""s technical instruction sheet for Troyshield F20(trademark) advises against mixing it with strongly alkaline bactericides, such as, for example, 1,3,5-tris(hydroxyethyl)hexahydrotriazine (Grotan BK(trademark)), because the stability of fungicidally and bactericidally active preparations based on IPBC is impaired.
There has thus been a search for potential ways of improving the stability of IPBC-based compositions for use as preservatives having a fungicidal and bactericidal action.
The prior art includes, for example, an almost white powder consisting of IPBC and a mixture of 1,3-bis(hydroxymethyl)-5,5-dimethylhydantoin and hydroxymethyl-5,5-dimethylhydantoin GlydantPlus(trademark), Lonza AG), which is used as a preservative for cosmetic preparations.
U.S. Pat. No. 5,496,842 and U.S. Pat. No. 5,428,050 disclose water-soluble compositions comprising a combination of iodopropynylbutyl compounds and N-methylol compounds. It is disclosed that compositions comprising IPBC and N-methylol compounds in a weight ratio of from 1:100 to 1:2000 are in the form of a concentrate powder which, as a water-soluble additive, can be added to industrial products, in particular bodycare products, which then include from 0.01% to 2% of these compositions. The N-methylol compounds mentioned in U.S. Pat. No. 5,496,842 and U.S. Pat. No. 5,428,050 do, however, include compounds which are not compatible with IPBC, for example 1,3,5-tris(hydroxyethyl)-hexahydrotriazine.
EP 0327220 B1 discloses a combination of an iodopropynyl compound with known formaldehyde donors. The disclosed compositions include, as preferred iodopropynyl compound, IPBC and, as formaldehyde donors, non-toxic and odorless compounds which are suitable for use in bodycare products, for example urea derivatives and dimethyloldimethylhydantoin. The compositions of EP 0327200 B1 are likewise added, for example, in the form of solid, water-soluble mixtures, to the products to be preserved.
The known pulverulent concentrates do, however, have a number of technical disadvantages, such as, for example, a tendency toward clumping, a relatively low dissolution rate, a tendency to form dust and the like.
Moreover, the use of odourless, i.e. usually nonvolatile, formaldehyde donors does not, in the case of certain applications, offer adequate antimicrobial protection in the gaseous phase, since no vapour phase of volatile, formaldehyde compounds is present.
In addition, the N-methylols in the form of liquid concentrates mentioned in U.S. Pat. No. 5,496,842 and U.S. Pat. No. 5,428,050 are not compatible with IPBC, i.e. are unstable and are thus also insufficiently stable in liquid products, such as cutting fluids, which are to be preserved. This is therefore a disadvantage particularly because in industrial products such as cutting fluid emulsions, desired pH stabilization and buffering is achieved inter alia by adding basic, tertiary amines.
The object of the present invention is to provide compositions which protect industrial products against bacterial attack and fungal infestation over extended service lives. The novel compositions should themselves be sufficiently stable and should not decompose under various conditions. In addition, they should be easy to handle and have advantageous technical properties and be easily incorporated into industrial products.
Another object of the present invention is to provide biocidal compositions which include iodopropynylbutyl compounds and formaldehyde donor compounds which are compatible therewith. It should be possible to meter these compositions into standard commercial industrial products, for example by adding a liquid preparation.
Another aim of the present invention is to provide compositions which have improved vapour phase effectiveness compared with the prior art and are sufficiently stable over a wide pH range.
A further object of the present invention is to provide industrial products, such as, for example, cutting fluids, which are distinguished from the prior art by increased stability and improved effectiveness.
This object is achieved by a composition which includes (a) an iodopropynylbutyl compound selected from iodopropynylbutyl esters, ethers, acetals, carbamates and carbonates and (b) one or more formaldehyde donor compounds, and is characterized in that the formaldehyde donor compounds are N-formals formed by the reaction or condensation of a monovalent or polyvalent, amino-substituted C1-C10-alkyl, -aryl or -aralkyl alcohol and a formaldehyde-supplying compound, and/or O-formals formed by the reaction of a monovalent or polyvalent C1-C10-alkyl, -aryl -aralkyl alcohol or of a glycol or glycol ether and a formaldehyde-supplying compound, and/or a combination thereof.
The novel preparations preferably comprise iodopropynylbutyl carbamate (IPBC), and the formaldehyde donor compound is preferably an N-formal selected from 3,3xe2x80x2-methylenebis(5-methyloxazolidine) (Mar 71(trademark)), 3,3xe2x80x2-methylenebis(tetrahydro-2H-1,3-oxazine) and 1-aza-5-ethyl-3,7-dioxabicyclo-(3,3,0)octane, particularly preferably a combination of 3,3xe2x80x2-methylenebis(5-methyloxazolidine) (Mar 71(trademark)) and IPBC.
The compositions comprising the novel iodopropynylbutyl compound and N-formals include the components in amounts, based on the composition, of from 0.1 to 20% by weight of iodopropynylbutyl compound and from 99.9 to 80% by weight of N-formal, preferably from 1 to 10% by weight of iodopropynylbutyl compound and from 99 to 90% by weight of N-formal. The composition particularly preferably comprises from 4 to 6% by weight of iodopropynylbutyl compound, in particular iodopropynylbutyl carbamate, and from 96 to 94% by weight of N-formal, in particular 3,3xe2x80x2-methylenebis(5-methyloxazolidine).
In addition or alternatively to the N-formals according to the invention, the novel compositions may also comprise O-formals formed by the reaction or condensation of formaldehyde-supplying compounds and mono- or polyvalent C1-C10-alkyl, -aryl or -aralkyl alcohols or glycols or glycol ethers, such as, for example, 1,2-propylene glycol hemiformal, ethylene glycol mono- and/or bisformal, butyldiglycol hemiformal, butylglycol hemiformal, benzyl glycol hemiformal, dipropylene glycol hemiformal and the like.
The compositions comprising the iodopropynylbutyl compound according to the invention and O-formals include the components in amounts, based on the composition, of from 0.1 to 20% by weight of iodopropynylbutyl compound and from 99.9 to 80% by weight of O-formal, preferably from 1 to 10% by weight of iodopropynylbutyl compound and from 99 to 90% by weight of O-formal. The composition particularly preferably comprises from 4 to 6% by weight of iodopropynylbutyl compound, in particular iodopropynylbutyl carbamate and from 96 to 94% by weight of O-formal, in particular from 96 to 94% by weight of 1,2-propylene glycol hemiformal.
Particularly suitable compositions are also those which comprise from 0.1 to 20% by weight, of an iodopropynylbutyl compound and from 99.9 to 80% by weight of a mixture of N- and O-formals, the weight ratio of N- to O-formals being from 10:1 to 1:10, preferably from 9:1 to 8:2 and particularly preferably from 2:1 to 1:2. These compositions preferably comprise from 1 to 10% by weight of iodopropynylbutyl compound and from 99 to 90% by weight of the mixture of N- and O-formals. Such a composition particularly preferably comprises from 4 to 6% by weight of iodopropynylbutyl compound, in particular iodopropynylbutyl carbamate, and from 96 to 94% by weight of the mixture of N- and O-formals, in particular from 96 to 94% by weight of a mixture of 3,3xe2x80x2-methylenebis(5-methyloxazolidine) and 1,2-propylene glycol hemiformal.
The novel compositions are preferably in stable liquid, viscous liquid or paste form, so that they are easy to handle and can be added easily to an industrial product at any time in order to preserve it.
In addition to the biocidally effective components, the novel compositions may comprise further additives and/or auxiliaries, such as emission-reducing additives, viscosity-modifying additives, wetting agents and solvents which have a favourable effect on the technical properties of the compositions, such as, for example, solubility in water, in total amounts of less than 90% by weight, preferably of less than 30% by weight and particularly preferably of less than 15% by weight. Here, the mixing ratios of the individual additives to one another are in the customary ranges known for biocidal compositions.
Particularly suitable compositions are those which comprise a solvent which is selected from 1,2-propylene glycol, 1-methoxy-2-propanol, phenoxypropanol and phenoxyethanol.
For example, the addition of certain glycols, preferably 1,2-propylene glycol, in amounts of from 1 to 20% by weight, based on the composition, has a positive influence on the odor of the compositions and reduces the emission of readily volatile substances, such as, for example, formaldehyde.
Particularly suitable compositions are those which, based on the composition, include the following components:
a) from 0.1 to 20% by weight, preferably from 1 to 10% by weight and particularly preferably from 4 to 6% by weight, of an iodopropynyl compound according to the invention and
b) from 99.8 to 80% by weight, preferably from 99 to 90% by weight and particularly preferably from 96 to 94% by weight, of a mixture of solvents and N-formals according to the invention or of a mixture of solvents and O-formals according to the invention or of a mixture of a combination of N- and O-formals and solvents and also other additives as described above, the weight ratio of formal to a solvent being from 50:1 to 1:10 and preferably greater than 9:1.
As well as the described additives and solvents, which contribute to improving the properties of the novel compositions, the latter may comprise further known biocidal active ingredients, such as, for example, isothiazolones or mercaptopyridines, of which N-octylisothiazolone (Kathon 893(trademark)) and 2-mercaptopyridine N-oxide, in particular in the form of its 40% strength aqueous sodium salt solution (Pyrion-Na(trademark)), are particularly preferred;
The composition may also comprise further additives which improve its stability.
In a specific embodiment of the present invention, the composition, as described above? comprises between 1% and 10% by weight of IPBC, between 85% and 98,5% by weight of 3-3xe2x80x2-methylene bis (5-methyloxazolidine) and between 0,5% and 5% by weight of a stabilizer selected from triethanolamine, pyriondisulfide, sodium sulfate or aluminium oxide.
The novel compositions are in the form of a stable liquid concentrate, a stable working solution prepared by diluting the concentrate, a stable emulsion or a stable suspension. The composition can thus be metered easily and also has a good shelf life and does not decompose under practical conditions. The good handling properties of the composition, compared with the storage, preparation and metering in of active ingredients present in two-component systems, are advantageous.
In particular, the novel composition is in the form of a concentrate, in which case the following requirements placed on concentrates are satisfied:
broad effectiveness (e.g. against bacteria, yeasts and fungi)
storage stability, transportation stability and thermal stability
relative insensitivity towards heat and light
compatibility with packing materials
adequate solubility in water and homogeneous distribution properties to achieve problem-free incorporation in the products to be preserved (e.g. aqueous solutions or hydrous products)
good incorporation into anhydrous or low-water products
vapour phase effectiveness
adequate pH compatibility, in particular up to pH 11
sufficiently low viscosity to enable simple metering.
The novel compositions may effectively be added to industrial products containing industrial preservatives, in particular container preservatives, fuel additives, cutting fluid preservatives, preservatives for cutting fluids which have been mixed with water, emulsions and dispersions in the coatings industry or in metalworking, household products, cosmetics and the like, so that the stability thereof and the service life of the finished products is increased compared with known systems. Increased stability of the novel compositions is particularly apparent from the lower tendency of the active ingredient to decompose, less discoloration and reduced formation of undefined decomposition products.
In addition to the customary constituents, the abovementioned industrial products thus comprise a novel composition whose components are sufficiently compatible both in the concentrate and also in the emulsion or suspension. The industrial products preferably comprise from 1 to 10% by weight, preferably from 2 to 5% by weight and in particular 2% by weight, of the novel composition.
Surprisingly, it has been found that the novel combinations of iodopropynylbutyl compounds and N- and/or O-formals, in particular the combination of iodopropynylbutyl carbamate (IPBC) and 3,3xe2x80x2-methylenebis(5-methyloxazolidine) (Mar 71(trademark)), have a stability which is significantly improved over the prior art, even if they are present in the form of liquid compositions, such as, for example, solutions or emulsions, in particular liquid concentrates, and are added to the abovementioned industrial products in such a form.
In addition, the effectiveness of the compositions is improved by the addition of further additives as in Patent claims 15 to 23, and, in particular, it is also possible to improve the effectiveness in the vapour phase.
Moreover, the novel compositions are adequately stable over sufficiently broad pH ranges which are relevant when the compositions are used in industrial products. Their stability is adequate in the pH range up to 12, in particular in the range up to pH 11, especially up to pH 9.
The improvements achieved in the compositions as regards stability, effectiveness and other technically relevant properties, such as pH stability and emission behavior, are illustrated by the examples below.